Yikes
The most important observation about market valuations here is that while a decade of zero interest rate policy has encouraged yield-seeking speculation in stocks, the resulting extreme in stock market valuations has also driven likely 10-12 year S&P 500 nominal total returns below zero. Investors are not likely to find an alternative to hypervalued stocks and bonds in some undiscovered asset that they can passively hold instead. The alternative is patient, value-conscious discipline, flexible to changes in valuations, market internals, and other factors.